The present invention relates to field effect transistor fabrication, and more specifically, to threshold voltage control of carbon-based field effect transistors.
Threshold voltage, Vt, control of carbon based field effect transistor devices (FET) such as carbon nanotube (CNT) FET devices relies on gate work function. Simple metal gates on the CNT FET devices may not generate the work functions needed to adjust the threshold voltage, partially because the CNT lattice will be destroyed using the conventional ion-implantation method with dopants to control the threshold voltage. As such, there are currently CMOS process flow limitations in controlling threshold voltage during the fabrication of the devices.